package main;

public class SerialTree {
    public static void main(String[] args) {

    }

    public String serialize(TreeNode root){
        if (root == null){
            return "#";
        }
        String lestStr = serialize(root.left);
        String rightStr = serialize(root.right);
        return root.val + "," + lestStr + "," + rightStr;
    }

//    public TreeNode deserialize()

}

